應用於中溫SOFC之氣化/重整爐之研究

Abstract

本研究共分兩個子題，一是中溫爐體效能改善，起因於固態氧化物燃料電池(SOFC)及燃料重整器等配件需在中高(650 ~ 800 oC)溫度持溫，因此前[李坤翔，2020]組製中溫爐(簡稱F01)可用於加熱及維持700 W中溫型SOFC正常操作，然而前數據顯示操作期間電池組加熱成本高居所有成本因素的第一位，佔67.5%，熱效益不佳，使發電不具可行之經濟效益。因此本研究提出一新設計，並實際組製兩種中溫爐體(簡稱F02及F02+)進行測試，期望降低爐體持溫時之熱散失。結過顯示兩種F02爐之熱散失功率明顯小於前[李]組製之F01爐體，在800 oC持溫時，熱散失功率由原先F01之1600 W降低至F02+之550 W，因此SOFC發電成本也由9.58 (NT$/kWh)減少至5.15 (NT$/kWh)。另一子題是嘗試以塑性成型法製備氧化鋅催化載體，摻入Ni/CeO2後，100小時長時間使用甲醇重整，650 oC測試之初期產氫濃度為63.2%優於氧化鋁球載體62.3%，但隨時間增長產氫濃度衰減也更快。由測試催化劑壽命後，可計算甲醇SOFC發電之總成本為5.90 (NT$/kWh)，優於台電火力燃油發電成本7.15 (NT$/kWh)，具經濟可行性。

This study consists of two sub-topics, one is IT-furnace thermal efficiency improvement, because solid oxide fuel cells (SOFCs), fuel reformer and other accessories need to maintaining at medium to high (650-800 oC) temperature. Therefore, Li [李坤翔, 2020] has demonstrated that assembling intermediate-temperature (IT-) furnaces, abbreviated as F01, can be used to heat and maintain normal operation of the 700W SOFC. However, Li’s data show that the cost of heating the SOFC stack during operation was the highest of all cost factors, accounting for 67.5%. But the thermal insulation of F01 was poor, making power generation not economically feasible. Therefore, this study proposed a new furnace design and assembled two IT furnaces (abbreviated as F02 and F02+) for testing in order to reduce the heat dissipation when the furnaces were holding. The results show that heat dissipation power of two F02 furnaces is significantly smaller than that of F01 furnace, and the heat dissipation power is reduced from 1600 W for the original F01 to 550 W for the F02+ at 800 oC, thus reducing the SOFC power generation costing from 9.58 NT$/kWh to 5.15 NT$/kWh. Another sub-topic is preparing a ZnO catalytic carrier (pd-ZnO) by plastic deformation (abb. as “pd”), doped with Ni/CeO2, and then reformed with methanol for 100 hr. The initial concentration of hydrogen production by pd-ZnO is 63.2% at 650 oC is better than that of 62.3% for the alumina carrier. But the hydrogen concentration declines faster with time, 48.6% and 55.8% respectively after 100 hr operation. After testing the catalyst lifetime, the total cost of methanol SOFC power generation is calculated to be 5.90 (NT$/kWh), which is better than Taipower's oil-fueling combustion power generation in cost of 7.15 (NT$/kWh), and this work show the investigation to be economically feasible.